1 : a long, thin mark that is a different color from its background

He left streaks where he wiped the glass.

The miners had streaks of coal dust on their faces.

2 : a quality that is noticeable especially because it is different from a person’s other qualities — usually singular

streak of stubbornness = a stubborn streak

She has an adventurous/competitive streak in her.

He has a mean streak.  [=a tendency to be mean]

3 : a period of repeated success or failure

a lucky streak

streak of 11 straight victories

a winning/losing streak  [=a series of wins/losses]

The team has recently been on a hot streak.  [=the team has been winning a lot of games recently]

4 : a long, narrow area or flash of light

streak of lightning/light